US3657773A

US3657773A - Apparatus for blending fibers

Info

Publication number: US3657773A
Application number: US824188A
Authority: US
Inventors: Joe R Whitehurst
Original assignee: Warner and Swasey Co
Current assignee: Barber Colman Co
Priority date: 1966-07-15
Filing date: 1969-05-13
Publication date: 1972-04-25
Anticipated expiration: 1989-04-25

Abstract

Apparatus for blending fibers in which a plurality of primary drafting units for drafting respective masses of textile fibers are arranged to direct fibrous webs therefrom to a common secondary drafting unit, and wherein means are provided between the primary and secondary drafting units for successively arranging the fibrous webs in stacked superposed relationship, and including means for aiding in the advancement of the webs into stacked relationship and to the secondary drafting unit.

Description

[4 1 Apr. 25, 1972 United States Patent Whitehurst [54] APPARATUS FOR BLENDING FIBERS 460,083 9/1891 Dunham etal... 630,813 8/l899 Meats............... 2,972,786 3,067,471

[72] Inventor: Joe R. Whitehurst, Bessemer City, N.C.

'2/1961' Tabor.... 12/1962 3,304,584 2/-l967 Noda......... West et al.....

[73] Assignee: The Warner & Swasey Company, Cleveland, Ohio 3,327,356 9/1967 Andreani......

May 13, 1969 211 App]. No.: 824,188

[22] Filed:

3,421,186 l/l969 Halleuxetal............................

Primary Examiner-Dorsey Newton Attorney-Patron, Bell, Seltzer, Park & Gibson Related U.S. Application Data [62 Division of Ser. No. $65,580, Jul

ABSTRACT y 15, 1966, Pat. No.

Apparatus for blending fibers in which a plurality of primary drafting units for drafting respective masses of textile fibers are arranged to direct fibrous webs therefrom to a common secondary drafting unit, and wherein means are provided between the primary and secondary drafting units for succes- [51] lnt.Cl.'.... [58] Field oiSearch...................

sively arranging the fibrous webs in stacked superposed relationship, and including means for aiding in the advancement of the webs into stacked relationship and to the secondary drafting unit.

S T N m MA mm A e "w n E H N U no U 11 Drawing Figures m C 3 9 X5 31 M9 l. 9 l

3,432,890 3/l969 Burnhamet.

R25,520 2/l964 Whitehurst......

Patented April 25, 1972 3,657,773

5 Sheets-Sheet 1 INVENTOR. Joe- E. WHITEHURST ATTORNEYS Patented April 25, 1972 5 Sheets-Sheet 2 mvmmm: Joe E. WHITE-HURsT .13 MKMMC/Z, My, @1 9 WM.

Patented A ril 25, 1972 3,657,773

5 Sheets-Sheet 5 INVENTOR: Joc- E. WH\TEHLJ2$T ATTORNEYS Patented April 25, 1972 5 Sheets-Sheet ATTORNEYS Patented April 25, 1972 5 Sheets-Sheet 5 INVENTOR: JoE- E. WH \TE-HURST ATTORNEYS APPARATUS FOR BLENDING FIBERS This application is a division of my copending application Ser. No. 565,580, filed July 15, 1966, now U.S. Pat. No. 3,495,304 and entitled METHOD FOR BLENDING FIBERS.

This invention relates to an improved apparatus for blending textile fibers and is particularly concerned with the homogenous blending of different kinds of natural and/or man-made fibers which may be of different staple lengths.

The practice of mixing and blending cotton fibers by opening machinery before forming picker laps therefrom is well known. With the advent of many different types of synthetic staple fibers, the blending of such different types of synthetic fibers or the blending of one or more types of synthetic fibers with natural fibers has presented many difficulties in the textile industry because of inequalities in the surfaces of different types of fibers, variations in denier or tenuosity of different types of fibers, the necessity for producing accurate propor-' tions of different types of fibers in particular blends, etc. While some blending of different types of fibers has been carried out by use of opening machinery, such blends have generally been unacceptable for the manufacture of high quality yarn therefrom due to a nonuniformity in the distribution of the different types of fibers. Therefore, it is a more general practice to blend different types of fibers by various processes of drafting after the fibers have been carded and formed into slivers.

Various methods have been proposed heretofore for blending fibrous carded stock or slivers of different types and in various proportions. One such method has included the simultaneous drafting of groups of card slivers in which side-by-side slivers fed to a drawing frame were of different weights per unit length in accordance with the proportions of different fibers desired in the blend. However, such method has had many drawbacks. For example, certain carding machines could not be operated at maximum production because one or more carding machines might be producing a relatively heavy sliver while another or other carding machines might have to produce a substantially lighter sliver in order that, when several slivers from the several'carding machines were doubled on a drawing frame, the weight per unit length of each sliver could be properly proportioned with respect to the weight of the other slivers in order to obtain the desired blend. Even though the stock might be passed through several processes of drafting, the desired intimacy or distribution of the fibers in the blends has not been obtained in most instances because of the aforementioned side-by-side relationship of different types of slivers as they were fed to the drawing frame.

In another method, such as is disclosed in U. S. Pat. No. 3,216,064, issued Nov. 9, I965, to G. S. Kates, Jr., for example, the quality of the blend has been improved by directing two superposed groups or layers of side-by-side slivers of different types of fibers into a drawing frame. However, in the latter method, the different types of fibers still may not be distributed uniformly throughout the width of the web issuing from the drawing frame or the resulting condensed sliver formed therefrom. Such lack of uniformity in the blends is particularly objectionable when products made therefrom are dyed, which is usually the case, because some areas or regions of the blend will be of a different shade or color than other regions thereof so the product may have an undesirable spotty or mottled appearance.

In some instances the quality of the blend has been improved by doubling slivers of blended fibers previously processed on a drawing frame in the manner heretofore described through sliver lappers and/or ribbon lappers. However, this not only requires additional handling of the fibers, but the uniformity of the blend still is not entirely satisfactory, such as to avoid the aforementioned lack of uniformity in dyeing, because of the manner in which the different types and weights of card slivers were drafted initially, as stated earlier.

It is therefore an object of this invention to provide an improved apparatus for blending different types of fibers in which slivers or webs of each type of fiber are initially drafied through separate primary drafting units with the units being independently adjustable to aceomodate the respective types of fiber lengths, variances in draft, etc., and wherein the fibers issue from the primary drafting units in the form of thin, broad, flat fibrous webs which are then arranged in superposed or stacked relationship and pass directly from the primary drafting units through a common secondary drafting unit which drafts all the superposed webs simultaneously and forms them into a web or sliver of the desired weight per unit length for further processing.

Regardless ofthe relative slippage characteristics of the different types of fibers and any variation in draft effected to the different types of fibers, the apparatus is adjustable so that all the webs issue from the primary drafting units at substantially the same linear speed so as to obviate relative longitudinal displacement between the webs upon superpositioning the same and in their course to the secondary drafting unit. By this arrangement, the fibers in each web emerging from the primary drafting units may be of a different type or chemical structure, such as synthetic or other man-made fibers, and/or natural fibers. The fibers emerging from one or more of the primary drafting units also may be of substantially different average staple length than the fibers being drafted through other primary drafting units. By forming each type of fiber into a broad, flat web, each type of fiber is uniformly distributed throughout the width of the superposed webs so that a much more intimate and homogenous blending of the different types of fibers is effected than has heretofore beenpossible to my knowledge.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which:

FIG. 1 is a preferred arrangement of textile drawing machinery embodying the apparatus of the present invention;

FIGS. 2A and 2B are, collectively, a somewhat schematic, enlarged, top plan view of the drafting and blending apparatus shown in FIG. I with the various drafting units thereof being uncovered for purposes of clarity;

FIG. 3 is a fragmentary elevation, partially in section, taken substantially along line 3-3 in FIG. 2A and showing suitable web guiding means for guiding the drafted web from a corresponding primary drafting unit in its course to a secondary drafting unit; I

FIG. 4 is a vertical sectional view, mostly in elevation, taken substantially along line 4-4 in FIG. 2A and particularly showing means for adjustably varying the intermeshing relationship of the delivery rolls of the corresponding drafting unit;

FIG. 5 is anenlarged fragmentary vertical sectional view, mostly in elevation, taken substantially along line 5-5 in FIG.

FIG. 6 is a vertical sectional view taken substantially along line 6+6 in FIG. 2A;

FIGS. 7 and 8 are somewhat schematic illustrations of draft gearing arrangements or gear trains such as may be associated with each of the drafting units in FIGS. 2A and 2B for determining the amount of draft imparted to corresponding fibers by each corresponding drafting unit, and in this instance, being taken substantially along respective lines 7-7 and 8-8 in FIG. 2A;

FIG. 9 is an enlarged fragmentary vertical sectional view through the web-supporting and guiding table or platform, taken substantially along line 9-9 in FIG. 2A and showing a preferred arrangement of calender rolls associated with each primary drafting unit; and

FIG. 10 is an enlarged fragmentary elevational view taken substantially along line 10-10 in FIG. 9, showing a preferred means facilitating adjustably varying the intermeshing relationship of the fluted calender rolls and an associated means for applying downward pressure to the corresponding top fluted calender roll.

Generally, the preferred apparatus of this invention cornprises a plurality or row of individual side-by-side primary drafting units. there preferably being three or more such primary drafting units, and four of which are shown in FIG. 1, and in combined FIGS. 2A and 28, generally designated at I, ll, Ill and IV, respectively. Fibers from the primary units are directed to a common secondary drafting unit V. Essentially, each primary drafting unit may be self-contained to the extent that (a) each unit may draft a different type of fibrous material than the others, (b) each unit may impart a different amount of draft to the material than the others, and (c) the weight per unit length of the material being received by and delivered from each primary drafting unit may be different from that of the other primary drafting units, although the bottom front or delivery rolls of all the primary drafting units and the bottom back or feed roll of the secondary drafting unit may be directly interconnected or driven by a common drive means in the instant embodiment of the invention, as will be later described. By directly interconnecting all the primary drafiing units, uniform output speed of fibers from the primary units is obtained with respect to each other even though periods of accelleration and deceleration of the drafting units may occur when starting and stopping the same.

As shown, the textile material entering each primary drafting unit l-lV is in the form of a plurality of slivers S, such as card slivers, drawn from a suitable creel including supply cans C. Primary drafting units l-lV deliver the textile material, in the form of respective thin, veil-like, broad, fiat fibrous primary webs W1, W2, W3, W4 onto respective curled guide plates 20 which curve downwardly and beneath themselves to invert the respective webs and change their direction of movement by about 90 as they are deposited upon a table or platform 21 and successively formed into stacked or superposed relationship, resulting in a common multilayered or composite web W5 Each web W1-W4 is drawn or pulled from the respective primary drafting unit over the respective guide plate 20 and along table 21 by a respective calendering device 24 which is constructed to maintain the desired tension draft in the webs while compacting successively superposed. webs to assist in homogenous blending of the fibers thereof. Composite W5 is thus formed of the stacked superposed webs Wl-W4 and passes through secondary drafting unit V which is operatively connected to primary drafting units l-lV to blend and draft the composite web and deliver the same in the form of a web which may be taken up on a suitable roll, not shown, or which may be condensed into a blended sliver S' and coiled into a can 25 for further processing.

Each drafiing unit l-V may comprise a plurality of sets of top and bottom drafting rolls, there being four sets of top and bottom drafting rolls provided for each drafting unit, in this instance. The top and bottom drafting rolls of each drafting unit are indicated at 31-34 and 31'34', respectively. Although the bottom drafting rolls of drafting units II-V are not shown, the drafting rolls of all the drafting units may be arranged substantially in the manner of drafiing unit I in FIG. 6. As shown in FIG. 6, all the drafting rolls preferably are fluted longitudinally thereof and the maximum depth of intermeshing relationship of each set of top and bottom drafting rolls preferably is limited by means to be later described. However, although it meshing'relationship of the fluted delivery rolls of the primary drafting units so that the speed of all the primary webs W1-W4 may be substantially uniform with all the bottom delivery rolls 34' rotating at a common speed, while allowing for tendencies of different types of fibers to slip different amounts relative to the respective drafting rolls.As to the tendency for different types of fibers to slip different amounts,

tests have shown that, in a typical drafting unit utilizing a set of fluted delivery rolls, such as rolls 34, 34' of FIG. 6, rotating at a given speed and positioned at a given intermeshing depth, the delivery speed of separately drafted different types of fibers varied from about 100 f.p.m. (feet per minute) to about 1 l0 f.p.m. For example, a web fonned only of Acrilsn fibers (acrylic staple) issued from delivery rolls at about 100 f.p.m., a web formed only of Dacron fibers (polyester staple) issued from delivery rolls at about 104 f.p.m., and a web formed only of cotton fibers issued from delivery rolls at about 110 f.p.m. A blend of about 50 percent cotton fibers and about 50 percent synthetic fibers issued from corresponding delivery rolls at about 105 f.p.m. Further variation in delivery speed of the webs has also been experienced in changing from one denier and/or staple length to another. it is axiomatic that such variations in delivery speeds cannot be'tolerated if the required weight per unit length and distribution of fibers are to be achieved in the composite web W5 and the resultant drafted material made therefrom. Conversely, if it is assumed that the fibers being drafted through each primary drafting unit l-lV are of a different type than the fibers being drafted through the other drafting units, it may be necessary to deliver the webs W1-W4 from the respective units at slightly diflerent speeds to allow for differences in stretchability of the different webs while providing for sufficient tension draft therein to prevent relative longitudinal movement between the primary webs'as they are successively superposed. I Since all the drafting rolls 31-34, 31'34' of each draftin unit preferably are in the form of fluted rolls, each set of top and bottom drafting rolls preferably is provided with means limiting the extent of interrneshing relationship thereof. Accordingly, each end of each bottom drafting roll may be journaled in a bearing 36 (FIGS. 4 and 5), which is preferably an is necessary that the top and bottom front or delivery rolls 34,34 of each primary drafting unit I-IV are fluted in the particular disclosed embodiment of the invention and that all the bottom delivery rolls of the primary drafting units are of the same diameter, it is to be understood that the remaining top drafting rolls 31-33 and/or the remaining bottom drafting rolls 31'-33' of the primary drafting units I-lV may be of the smooth-surfaced or cushion type. All the drafting rolls of the secondary drafting unit also may be of the smooth-surfaced or cushion type.

in the disclosed embodiment of the invention, the top and bottom delivery rolls 34, 34' of each primary drafting unit are fluted, with all the bottom delivery rolls 34 of the primary units being of about the same diameter, and means are proanti-friction bearing and fits in a substantially U-shaped hearing block 37. Each bearing 36 is provided with an enlarged portion 40 thereon whose diameter may be approximately the same as the pitch diameter of the corresponding fluted bottom roll. Also, each end of each top drafting roll may be joumaled in a bearing 41, which is preferably an anti-friction bearing, and whose reduced end portion fits loosely in the corresponding block 37, and wherein each bearing 41 has an enlarged portion 42 thereon. Preferably, the enlarged portion 42 of each bearing 41 has a removable thin-walled spacer sleeved 43 snugly or slidably mounted thereon which may normally bear against the upper surface of the enlarged portion 40 of the corresponding bottom roll bearing 36 therebeneath, thus limiting the extent of intermeshing relationshipof the flutes of the corresponding set of top and bottom drafting rolls. The reason why a sleeve 43 is preferred on the enlarged portion 42 of each bearing 41 is to facilitate ease in varying the intermeshing relationship of a corresponding set of rolls simply by removing spacer sleeve 43 from the enlarged portion 42 of the top roll bearing 41 at each end of a corresponding top roll and replacing the same with another sleeve of the same internal diameter but of a slightly diflerent external diameter. If

desired, sleeve '43, on'the enlarged portion 42 of each top roll operation of the drafting units as well as during any periods of I acceleration and deceleration of the same. As shown in FIGS. 2A and 2B, the bottom delivery rolls of adjacent primary units may be rigidly interconnected by corresponding connector shafts 50 therebetween and suitably secured thereto, as by means of a positive clutch 51 and a sleeve 52. The distal ends of the bottom delivery rolls of primary drafting units I and IV have respective extension shafts 54, 55 fixed thereto suitably journaled on the frames of the corresponding units 1, IV.

Extension shaft 55 is coupled to the output shaft of a suitable gear transmission device 56 (FIG. 23) carried by the frame of drafting unit IV and whose input shaft is operatively connected to a stub shaft 57, as by sprocket wheels 60, 61 and an endless sprocket chain 62. Stub shaft 57 may be driven from the bottom back or feed roll 31 of secondary drafting unit V through a gear train 63. intervening gears, which may be identical for each drafting unit and will be later described, connect the bottom delivery roll of secondary drafting unit V to the other bottom drafting rolls thereof, and a motive means 65, such as an electric motor, drives the bottom delivery roll of secondary unit V, thus providing a common drive means for all the drafting units I-V.

As heretofore stated, after composite web W5 is drafted, it may be formed into sliver S and coiled into can 25. Therefore, the drafted web from secondary drafting unit V is shown being drawn through a condenser 67 and a trumpet 70 by a pair of calender rolls 71, preferably of the fluted intermeshing type shown in my U. S. Pat. No. Re.Re. 26,135, dated Jan. 3, 1967. Rolls 71 feed sliver S through a suitable coiler mechanism 72 into can 25. One of the calender rolls 71 may be journaled on a shaft 73 and the other calender roll 71 may be fixed on a shaft 74.

Shafts

73, 74 are carried by the frame of drafting unit V and shaft 74 may be driven from the bottom delivery roll 34' of drafting unit V by a gear train 76. The shaft of motor 65 may be connected to the delivery roll of secondary drafting unit V by a suitably controlled clutch 77 (FIG. 2B) as is well known.

It is thus seen that all the drafting units lV are driven by motor 65 and that the speed of the delivery rolls 34, 34' of all the primary drafting units I-IV is of a fixed ratio to the speed of the feed rolls 31, 31' of secondary drafting unit V. Means are also provided for varying the draft imparted to the textile material by each of the drafting units independently of the others without necessarily changing the speed of the delivery rolls, thus permitting the drafting of a type of fibers through any one of the primary drafting units I-IV different from the type being drafted through any one or more of the other primary drafting units. Also, as exemplified in FIG. 6, the sets of drafting rolls 31, 31'; 32, 32; 33, 33 and 34, 34' of each drafting unit I-V are relatively adjustable on corresponding roll stands 80 independently of the drafting rolls of the other drafting units so that each primary drafting unit may draft fibers of different average staple length than the fibers being drafted by another or all the other primary drafting units. Accordingly, as shown in FIG. 6, each roll stand 80 may have a longitudinal slot 81 in its upper bridging portion through which a screw 82 for each bearing block 37 extends for securing the bearing blocks in the desired adjusted position.

The means for varying the amount of draft and imparting rotation to the intermediate and back drafting rolls of each drafting unit comprises a pair of gear trains (FIGS. 7 and 8) adjacent opposite sides of each drafting unit and which transmit rotation from each bottom delivery roll 34' to the remaining bottom rolls of the respective unit. The top drafting rolls are driven by engagement with the bottom drafting rolls or stock passing therebetween, as is usual. In FIGS. 7 and 8, which represent any one of the drafting units I-V, it will be observed that the bottom delivery roll 34' there shown has a small gear 83 (FIG. 7) fixed thereon meshing with a larger crown gear or change gear 84 mounted on a stub shaft85 in fixed axial relation with a gear 86 meshing with a gear 87 fixed on rear intermediate bottom drafting roll 32'. Stub shaft 85 may be in the form of a shoulder bolt adjustable in a slotted bracket 90 (FIG. 28) to accommodate change gears 84 of different sizes for changing the relative speeds of rolls 32, 34' and thereby to change the amount of draft effected by the corresponding drafting unit without changing the speed of delivery rolls 34, 34.

The end of each rear intermediate drafting roll 32' remote from gear 87 has a gear 91 fixed thereon (FIG. 8) meshing with a pair of

gears

92, 93 which may be mounted in the same manner as change gear 84 and have

respective gears

94, 95 in fixed axial relation therewith.

Gears

94, 95 mesh with respective gears 96, 97 fixed on front intermediate drafting roll 33' and feed roll 31, respectively. Gears 92-94 also may be replaced by gears of different sizes to effect changes in draft as may be required when changing from one type of stock to another.

Any suitable means may be employed for applying yieldable downward pressure to each end of each top drafting roll 31-34, such as is shown in U. S. Pat. Nos. 2,412,357 and 3,143,772, for example. Such pressure applying means may include a separate spring-loaded plunger 98 (FIGS. 4 and 5) bearing against each bearing 41 or its sleeve 43. The springloaded plungers at each side of each drafting unit may-be carried by supports 99 overlying the corresponding bearings 41.

As stated earlier, primary webs Wl-W4 are drawn along table 21 by calendering devices 24. As shown in FIGS. 2A and 2B, table 21 is in the form of a row of plates 100 whose proximal ends are separated as in FIG. 10 to accommodate calendering devices 24. Plates 100 are suitably secured to corresponding bearing blocks 106 mounted on brackets 101. Each bracket 101 may take the form of a cantilever (FIG. 9) suitably secured to the frame of the corresponding primary drafting unit. As shown in FIGS. 9 and 10, each calendering device 24 may comprise a pair of top and bottom intermeshing fluted calender rolls 102, 103 whose reduced opposite ends are rotatably mounted in respective top and bottom bearings 104, 105 mounted in substantially U-shaped bearing blocks 106. The diameter of bearings 105 and a sleeve 107 on each bearing 104 may be about equal to the pitch diameter of the fluted portions of respective calender rolls 103, 102. Sleeves 107 are provided for a purpose similar to that of the sleeves 43 on top roll bearings 41 (FIGS. 4 and 5); i.e., to permit changing the depth of mesh of each top calender roll 102 with the respective roll 103 in accordance with the desired speed of the webs while maintaining desired tension draft therein.

Calender rolls 102, 103 preferably are of greater diameter than drafting rolls 31-34, 31'34', and, thus, the weight of each top calender roll 102 may serve to cause each top calender roll to engage the corresponding textile web or webs with the desired pressure. If desired, however, pressure applying means of the type heretofore described for the top drafting rolls may be used for the top calender rolls 102. In FIGS. 9 and 10, for example, a spring-loaded plunger 1 10 is shown bearing against each bearing sleeve 107. The stem of each plunger 110 is loosely mounted in a sleeve 111 carried by a bar 112 fixed to and extending between bearing blocks 106. A compression spring 113 engages the flanged upper portion of sleeve 111. Spring 113 also engages a washer 114 adjustably supported on the stem of plunger 110 by a nut 115, whereby the force of spring 113 acting on plunger 110 may be adjusted. A suitable clearer device or board 116 (FIG. 9) may be supported by each bar 1 12 to engage and prevent excessive accumulation of fibers on each top calender roll 102.

In this embodiment of the invention, the drafting rolls of all the drafting units l-V are conveniently on about the same level. Therefore, the front or foremost plate 100 of table 21 is inclined upwardly and forwardly (FIG. 1) to guide the composite web W5 to the drafting rolls of secondary drafting unit V. A carrier device 120 may be provided adjacent the upper edge of the foremost plate 100 of table 21 to assist in advancing composite web W5 to drafting unit V. Carrier device 120 comprises a pair of intenneshing fluted rolls 121 which may be mounted on the frame of secondary drafting unit V in the same manner as that in which calender rolls 102, 103 are mounted on bracket 101 in FIGS. 9 and 10. Therefore, a

detailed description and illustration of carrier device 120 is deemed unnecessary.

The bottom calender rolls of all the calendering devices 24 and carrier device 120 are preferably of the same diameter and may be driven at the same speed and at a speed in fixed ratio to the speed of the primary drafting units from a jack shaft 125 extending between table 21 and the front portions of the frames or housings of the primary drafting units. Suitable take-off gearing 126 connects bottom roll extension shaft 54 (FIG. 2A) to jack shaft 125 for driving the same in proper timed relation to the bottom delivery rolls 34 of primary units I-IV. Shaft 125 is joumaled in power transmission or gear units 130, one of which is mounted on each bracket 101 (FIG. 9). With the exception of the foremost transmission unit 130 in FIG. 2B, the output shafts of the remaining transmission units 130 may be connected to corresponding bottom calender rolls 103 by a positive clutch means 131. Each power transmission unit 130 may be of a type shown in FIG. 7 of U. S Pat. No. 2,975,489, to which reference is made for a detailed description thereof. It will be observed in FIG. 28 that a sprocket wheel 133 may serve the same purpose as one of the clutch means 131 to drive the bottom roll of carrier device 120 by means of a sprocket chain 134 and another sprocket wheel 135.

Suitable spool-shaped selvage guides 140 (FIGS. 2A, 2B and 3) may be adjustably mounted on table 21 and on the rear portion of the frame of secondary drafting unit V for guiding and smoothing the selvages of the webs as shown in FIGS. 2A and 28 during advancement of the same from the primary to the secondary drafting units. The selvage. guides 140 may be mounted as shown in FIG. 3, wherein a pair of the selvage guides are shown engaging opposite selvages of primary web W1. Each selvage guide 140 may have a reduced stem 141 penetrating a transverse slot 142 in table 21 and on which a washer 143 and nut 144 are mounted for securing each selvage guide in adjusted position.

In setting up the apparatus for operation, it is desirable that the feed rolls 31, 31' of the primary drafting units have an evening effect on the fibrous material being directed into the same, particularly when such fibrous material is in the form of groups of individual slivers S being drawn from'individual cans C as shown in FIG. I. To this end, the diameters of the sleeves 43 (FIG. 5) and the enlarged portions of the bearings 36 should be such relative to the diameters of the feed rolls 31, 31' of the primary drafting units l-IV that the top feed rolls thereof will be supported by the slivers S instead of by engagement of the spacer sleeves 43 with the enlarged portions 40 of the corresponding bearings 36. By such an arrangement, the feed rolls 31, 31' of the primary drafting units I-IV will advance the slivers S into the drafting zones between each set of feed rolls 31, 31' and the next succeeding set of drafting rolls 32, 32' at relatively faster speed when a relatively thin place in the slivers S being directed to the corresponding primary drafting unit is passing between the corresponding feed rolls 31, 31 Conversely, when a relatively thick place or a place of higher density in the corresponding slivers is passing between the feed rolls 31, 31', the speed of the slivers S entering the corresponding drafting zone will be decreased, thus contributing to uniformity in the density or weight per unit length of the webs W1-W4 being formed. The diameters of the sleeves 43 and the enlarged portions 40 of the bearings 36 relative to the diameters of the fluted portions of the remaining drafting rolls 32-34, 32-34 of all the primary drafting units l-IV and of all the drafting rolls of the secondary drafting unit V should be such that the fibrous material being drafted thereby will not normally raise the corresponding top drafting rolls; i.e., the corresponding spacer sleeves 43 (FIG. 5) normally will rest upon the enlarged portions 40 of the corresponding bottom roll bearings 36 at all times. Sleeves 43, on feed rolls 31, 31' of the primary units I-IV prevent the bottoming of corresponding top rolls 31 against bottom'rolls 31 It is important that the weight per unit length of each primary web W1-W4 is maintained constant and in accurate proportions to the weight of the other primary webs then being drafted through the primary drafting units l-IV so that the proportions of various types of fibers present in the composite web W5 meet the required specifications which may appear on labels applied to various products made from the fibers thus blended. On the other hand, it is also important that the delivery or linear speed of all the primary webs Wl-W4 issuing from the primary drafting units I-lV is substantially the same with consideration being given to the aforementioned tendencies for difi'erent types of fibers to slip different amounts relative to the drafting rolls, as well as the necessity for maintaining the primary webs Wl-W4 under proper tension draft. Further, the tension draft applied to the various webs as they advance along table 21 may vary slightly between successive calendering devices 24 and between the foremost calendering device 24 and and the carrier device (FIG.'

It is apparent, therefore, that the diameters of the sleeves 43 on the top roll bearings 41 of the various top delivery rolls 34 may vary at each primary drafting unit relative to the other primary drafting units. Of course, if the delivery speed of any one of the primary webs Wl-W4 becomes relatively high or low in order to accommodate all the conditions mentioned heretofore, it is apparent that any changes thus effected in the amount of draft to be imparted to the corresponding fibrous material by the corresponding drafting unit would also change accordingly and may be compensated for by making appropriate changes in the size of the corresponding gear 84 (FIG. 7) and/or in the gears 92-95 (FIG. 8) of the corresponding primary drafting unit. The desired speed of the feed rolls 31, 31' of the secondary drafting unit may be attained by making appropriate changes in the size of one or more of the gears in the gear train 63 (FIG. 2B).

Generally, any drafted fiber web is thicker longitudinally of its central portion than it is at its outer edges. This results in the web gradually increasing in width when it is being pulled between web advancing rolls, such as rolls 102, 103 (FIG. 9). I have discovered that, owing to the fact that synthetic fibers have slicker or smoother and more slippery surfaces than natural fibers, such as cotton fibers, synthetic fiber webs spread laterally when being pulled, to a greater extend than cottonwebs. Therefore, when blending synthetic and cotton fibers according to the instant invention, the slivers S are so arranged upon entering the respective primary drafting units l-IV that any synthetic fiber web or webs emerging therefrom are compensatively narrower than any cotton web or webs emerging therefrom so that, by the time that the composite web W5 formed therefrom reaches the secondary drafting unit V, the pulling force applied uniformly throughout the width of the webs will have caused the synthetic fiber web or webs to increase in width to a greater extent than the natural fiber web or webs so that all the webs of the composite web W5 will be of substantially the same width, thus further contributing to uniformity of the blend.

In accordance with this invention, it can be appreciated'that each primary drafting unit (1) is capable of drafting textile fibers of a difi'erent type and/or average staple length than that of the fibers being drafted by the other primary drafiing units, (2) is capable of applying a different amount of draft to corresponding fibers than that applied by the other primary drafting units, and (3) may deliver the corresponding primary web therefrom at substantially the same speed as that at which the primary webs are delivered from the other primary drafting units and in accordance with the speed at which the webs are to be drawn into the secondary unit V.

Even though the bottom delivery rolls 34' of all the primary drafting units I-IV may be of the same diameter and rotate at the same speed, and the fibers being drafted by any one of the primary units may slip relative to corresponding drafting rolls to a greater or lesser degree than the fibers being drafted by another or others of the primary units, it should be noted that the delivery speed of all the primary webs may be substantially the same and that minor adjustments may be made in the delivery speeds of the primary webs issuing from the primary drafting units, without changing the speed of the delivery rolls 34' thereof, thus insuring that each primary web may be subjected to the required amount of tension draft in its course to the table 21. Further, it should be noted that the primary webs are stacked successively in superposed relationship so that at least one of the primary webs is sandwiched between two other primary webs, and that the amount of tension draft applied to the primary webs may be varied in their course along table 21 and to secondary drafting unit V by making appropriate adjustments in the interrneshing relationship of the fluted calender rolls of calendering devices 24 and carrier device 120 in the manner heretofore described.

it is apparent that the greater the number of layers of fibers, as successive primary webs are deposited upon a preceding web or webs, the lesser may be the amount of tension draft required therein, although the total amount of tension draft may be accumulative as the number of layers of fibers increases. For example, a tension draft of 1.04 may be required in the first primary web W1, an accumulated tension draft of 1.05 may be required in the two superposed primary webs W1, W2, an accumulated tension draft of 1.06 may be required in the three superposed webs W1, W2, W3, and an accumulated tension draft of 1.07 may be required in the completed composite web W5. 1

Another important feature of the instant invention is that the composite web W formed by superposing the plurality of primary webs Wl-W4 passes directly from the primary units into the secondary drafting unit V which drafts and reduces the composite web to the final desired weight per unit length, either in the form of a web which may be rolled up or which is condensed into a final sliver and coiled into a can for further processing. The superposing of primary webs, wherein one or more of the webs may be formed of a different type or length fibers than the other webs, effects a uniform distribution of the fibers of each web throughout the width of the composite web and the drafting of the composite web through the secondary drafting unit blends and intersperses the various types of fibers with each other in a homogenous manner to produce a more thorough blending of the various fibers and a more uniform weight per unit length of the fibrous material issuing from the secondary drafting unit than has heretofore been attainable to my knowledge.

As an example of the complicated types of blends of fibers which may 'be obtained by practicing the method of the present invention, it may be assumed that a secondary sliver S weighing 60 grains per yard is to be obtained having 20 percent cotton fibers of about 1 inch average staple length, 30 percent Dacron fibers of about 2 inches average staple length, 25 percent Orlon fibers of about 1 9/16 inches average staple length and 25 percent Acrilan fibers having 3 inches average staple length therein. It may be assumed further that the sliver S to be obtained is to be made from card slivers, each of which weighs 60 grains per yard. Although there are various ways in which the various types of card slivers may be arranged in the primary drafting units l-lV to obtain the desired blended sliver therefrom, one example as to how the card slivers may be arranged will now be given.

In setting up the apparatus, ends or card slivers of cotton having 1 inch average staple length may be directed from separate cans C into primary drafting unit l; 16 ends of Dacron fibers having an average staple length of 2 inches may be directed from separate cans into primary drafting unit II; 10 ends of Orlon fibers having 1 9/ l 6 inches average staple length may be directed into primary drafting unit 111; and 10 ends of Acrilan fibers having 3 inches average staple length may be directed into primary drafting unit IV. The total draft imparted to the fibers at the primary drafting units I-lV would be 5, 5.3, 4 and 4, respectively. Thus, the primary webs Wl-W4 issuing from the drafting units l-IV would weigh 120, 180, 150 and 150 grains per yard, respectively, and the composite web W5 formed therefrom thus would weigh 600 grains per yard. The 600 grain-per-yard composite web W5 would then be subjected to a draft of 10 as it is passed through secondary drafting unit V and condensed through condenser 67 and trumpet 70 to form the blended sliver S weighing 60 grains per yard.

It can thus be appreciated that the delivery speed of an amount of draft imparted to the fibers by the secondary drafting unit V are substantially greater than that of each primary drafting unit.

l-leretofore, the only method I am aware of by which different types of card slivers could be blended in accurate pro-,

portions to obtain a complicated blend such as that described has been to produce card slivers of different weights per unit length and then draft several such different types of slivers through a common drafting unit. Even them, many propor tions of different types of fibers could not be obtained. Obviously, variation in the size of card slivers has undesirably reduced the production capabilities of one or more carding machines in the mill. in producing a 60 grain-per-yard blended sliver of the type mentioned in the foregoing example, but practicing the prior art method, as many as four or more different sizes of card slivers varying from about 44 to 60 grains per yard may be required. Also, the various types of fibers would not be distributed, intermixed or drafted with the uniformity or efficiency obtainable according to the instant method.

It is important to note that the primary webs Wl-W4 are crimped by the fluted drafting rolls of the primary drafting units to lend tensile strength thereto to assist in preventing rupture of the thin primary webs as they pass in engagement with the curled guide plates 20. This is particularly important with high speed operation of the delivery rolls 34, 34' of the primary drafting units l-IV. A further crimping of the webs occurs at each of the calendering devices 24 and the carrier device which not only lends tensile strength to the various webs as they are being advanced along table 21 to secondary drafting unit V, but also intermixes'the fibers of adjacent superposed webs in the formation of the composite web W5, thus further assisting in the homogenous distribution of the various types and lengths of fibers throughout the blend.

Although the fibrous material or stock is shown in the accompanying drawings being directed to the primary drafting units l-lV in the form of slivers being drawn from individual cans, it is contemplated that the incoming stock may be taken from sliver lap rolls or ribbon lap rolls. However, since it is necessary that all of the fibers are withdrawn from any one sliver lap roll or ribbon lap roll at a given speed, the spacer sleeves 43 (FIG. 5) for the feed rolls 31, 31' of any primary drafting units receiving stock from a sliver lap roll or ribbon lap roll would have to be of such diameter that they would also remain in engagement with the enlarged portions 40 of the corresponding bottom feed roll bearings 36 at all times during operation of a corresponding primary drafting unit or units, since a variation in the rate of feed of various portions of the webs coming from the ribbon lap rolls or sliver lap rolls to a particular drawing frame could not be tolerated.

In the drawings and specification there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

I claim:

1. Apparatus for blending textile fibers comprising a plurality of primary drafting units each including pairs of drafting rolls defining a plurality of drafting zones,

at least one of the primary drafting units including means for varying the effective length of the drafting zones thereof relative to the effective length of the drafting zones of at least one other of the primary drafting units so that said one of the primary drafting units is adapted for drafting fibrous material of a different staple length from the fibrous material passing through said one other primary drafting unit, said primary units being adapted to receive and draft separate respective masses of textile fibers and to deliver the thus drafted fibers therefrom in the form of respective broad, thin, fibrous webs,

each primary drafting unit also including l 1 a pair of intermeshing fluted delivery rolls, and means for varying the extent of intermeshing relationship 1 of the delivery rolls of the primary units relative to each other for controlling the speed at which the corresponding webs emerge from the respective primary drafting units, a secondary drafting unit adjacent said primary drafting units, driving means operatively connected to said primary and secondary drafting units for driving the same in correlated relationship and maintaining the surface speed of all of the delivery rolls of the primary drafting units in substantially constant relation with respect to each other at all times, and means for successively arranging the webs emerging from said primary drafting units in superposed relationship and directing the same into said secondary drafting unit and including pairs of intenneshing fluted calender rolls operatively associated with said drafting units for applying progressively increasing tension draft to the webs from said primary drafting units in their course to said secondary drafting unit so as to aid in unitary longitudinal movement of the superposed webs to said secondary drafting unit and for applying lateral crimp to the superposed webs to enhance the cohesiveness and tensile strength of the webs,

means for varying the extent of intermeshing relationship of said calender rolls, and

selvage guides positioned downstream of each primary drafting unit for guiding engagement with the opposing longitudinal edges of the webs.

2. Apparatus according to claim 1, in which said driving means comprises a common motor operatively connected to all of the drafting units.

3. Apparatus according to claim I, in which said primary drafting units are arranged in a row and in side-by-side relationship so that the webs emerge therefrom in substantially parallel relationship, and said means for arranging and direct-i ing the webs also includes elongate guiding and supporting means extending in front of and substantially parallel with the row of primary units for receiving and guiding the webs into said secondary drafting unit.

l t I I

Claims

1. Apparatus for blending textile fibers comprising a plurality of primary drafting units each including pairs of drafting rolls defining a plurality of drafting zones, at least one of the primary drafting units including means for varying the effective length of the drafting zones thereof relative to the effective length of the drafting zones of at least one other of the primary drafting units so that said one of the primary drafting units is adapted for drafting fibrous material of a different staple length from the fibrous material passing through said one other primary drafting unit, said primary units being adapted to receive and draft separate respective masses of textile fibers and to deliver the thus drafted fibers therefrom in the form of respective broad, thin, fibrous webs, each primary drafting unit also including a pair of intermeshing fluted delivery rolls, and means for varying the extent of intermeshing relationship of the delivery rolls of the primary units relative to each other for controlling the speed at which the corresponding webs emerge from the respective primary drafting units, a secondary drafting unit adjacent said primary drafting units, driving means operatively connected to said primary and secondary drafting units for driving the same in correlated relationship and maintaining the surface speed of all of the delivery rolls of the primary drafting units in substantially constant relation with respect to each other at all times, and means for successively arranging the webs emerging from said primary drafting units in superposed relationship and directing the same into said secondary drafting unit and including pairs of intermeshing fluted calender rolls operatively associated with said drafting units for applying progressively increasing tension draft to the webs from said primary drafting units in their course to said secondary drafting unit so as to aid in unitary longitudinal movement of the superposed webs to said secondary drafting unit and for applying lateral crimp to the superposed webs to enhance the cohesiveness and tensile strength of the webs, means for varying the extent of intermeshing relationship of said calender rolls, and selvage guides positioned downstream of each primary drafting unit for guiding engagement with the opposing longitudinal edges of the webs.

3. Apparatus according to claim 1, in which said primary drafting units are arranged in a row and in side-by-side relationship so that the webs emerge therefrom in substantially parallel relationship, and said means for arranging and directing the webs also includes elongate guiding and supporting means extending in front of and substantially parallel with the row of primary units for receiving and guiding the webs into said secondary drafting unit.